1. Field of the Invention
The present invention relates generally to a technique for handling a sheet, and more specifically to an apparatus and method for disposing the sheet adjacent a surface of a flexible member and wrapping the flexible member about itself with the sheet interposed between opposed surfaces of the flexible member.
2. Description of the Prior Art
In the art of electrophotography an electrophotographic plate comprising a photoconductive insulating layer on a conductive layer is imaged by first uniformly electrostatically charging the imaging surface of the photoconductive insulating layer. The plate is then exposed to a pattern of activating electromagnetic radiation such as light, which selectively dissipates the charge in the illuminated areas of the photoconductive insulating layer while leaving behind an electrostatic latent image in the non-illuminated area. This electrostatic latent image may then be developed to form a visible image by depositing finely divided electroscopic toner particles on the surface of the photoconductive insulating layer. The resulting visible toner image can be transferred to a suitable receiving member such as paper. This imaging process may be repeated many times with reusable photoconductive insulating layers.
The electrophotographic plate may be in the form of a flexible photoreceptor belt. These flexible belts include a substrate and a sensitive layer, the sensitive layer including an electrically conductive surface and at least one photoconductive layer. A common flexible photoreceptor belt comprises a substrate, a conductive layer, an optional hole blocking layer, an optional adhesive layer, a charge generating layer, a charge transport layer and, in some embodiments, an anti-curl backing layer.
These photoreceptor belts are usually thin and flimsy. Any considerable amount of handling of the belt, through, for example, shipping, can result in damage to the sensitive layer. Scratches, dents and other forms of damage to the sensitive layer, resulting from handling, can lead to degradation in image quality in printed material produced by the printing machine. Additionally, handling of the belt is made more difficult when the belt is in an unraveled state.
A technique for wrapping an elongate flexible loop with a sheet of protective paper is discussed in U.S. Pat. No. 5,163,265 to Darcy et al., the relevant portions of which are incorporated herein by reference. As indicated in the Wrapping Application, an elongate flexible loop or photoreceptor belt is packaged by wrapping it tightly about itself. Under normal circumstances, with many types of belts, the tight packaging is desirable; however, at least one situation can arise in which the tight wrapping can be quite undesirable. In particular, due to their relatively low thermal coefficient of expansion, belts used on the Xerox Copier 1065 exposed to temperatures in excess of ambient levels, tend to expand readily. When one of these belts is wrapped tightly, and subsequently heated, it has "nowhere to go", so that shear forces between belt substrate portions can increase beyond manageable levels. The inability to compensate for these unmanageable levels of shear forces can cause distortion throughout the sensitive layer of the belt in the form of "dimpling." Use of a dimpled belt will inevitably result in unacceptable copy quality. Hence it would be desirable to provide a technique that would minimize shear forces under the above-mentioned conditions and thereby eliminate dimpling.